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W. T. GARRATT. Method of Uniting the Two Halves of Cylinder. No 2f30,413.

Patented July 27, 1880.,

lnvenior [mam Witnesses N,PETERS, PHOTO-LITHQGRAPHER, W. sumac UNITEDSTATES PATENT OFFICE.

WILLIAM T. GARRATT, OF SAN FRANCISCO, CALIFORNIA.

METHOD OF UNITING THE TWO HALVES OF CYLINDERS.

SPECIFICATION forming part of Letters Patent No. 230,413, dated July 27,1880.

Application filed December 17, 1879. I

To all whom it may concern:

Be it known that I, WILLIAM T. GARRAT of the city and county of SanFrancisco, State of California, have invented a new and useful Method ofUniting the Two Halves of Cylinders, applicable to digesters for soapand candle manufacturers, as fully set forth in the followingspecification.

Digesters are'metal cylinders with closed ends, into which fatty matteris placed to be operated upon by steam at high temperature in theprocess of rendering or refining fatty substances, and are generallyconstructed of copper or cast-iron lined with copper, a common sizebeing, say, forty inches in diameter and twenty feet high.

It has heretofore been found necessary to make these cylinders in two ormore pieces, and the joints being formed of flanges bolted together havebeen found exceedingly troublesome in the matter of maintaining themtight and free from leakage, consequent upon the unequal expansion andcontraction they are subject to, as well as the action of the fats andaccompanying acids.

It is the object of the present invention to avoid these joints bymaking the digesters of cast-brass in one piece, or rather joining twoparts thereof by a process of fusion, as follows: First I cast the twoparts of the digester'A and B, as shown in Figs. 1 and 2 of theaccompanying drawings. 1 then take the part B, and embedit in themolding-floor to within about a couple of feet of its top. I then coverthe part of the cylinder projecting above ground with a box or flask, C,andfill in with dry sand, leaving an annular gutter or recess around theexterior and interior of the edge of the cylinder to form half of themold in which to cast the proposed joint D. The upper half of this jointis molded in a dry-sand cope, E, placed over the lower'half, and intowhich the lower edge of the cylinder A is inserted, as shown in Fig. 1,there being left, of course, an annular opening, P, in the upper part ofthe mold to receive the upper part of the cylinder. This upper part, A,of the cylinder is suspended from a crane. The two edges of the cylinderare brought to within about one-half inch of each other, and the mold,being provided with a gate, F, to pour in the mettle, and two or threerunners, Gr, to-allow the metal to run out, is then closed. The'hotmetal as it is poured in soon melts the edges of the cylinder whichproject into the mold, and as the metal passes out about as quickly asit is poured in there is no chance for cooling.

As soon as the edges of the cylinder are completely melted the runnersGare stopped,

0001. After a few minutes, when the metal has thoroughly set, allsupport which has been given to the upper half of the castingA must bewithdrawn, so as to permit the now rapidlyshrinking joint to maintainconnection with both halves of the casting. This is a most importantfeature, for if there be any strain upon the joint when shrinking incooling cracks will surely occur, perhaps immediately, though possiblynot for hours after the work is done. If the work is skillfully done aperfect union will be effected in the above manner, as shown in Fig. 2.

In Fig. ],H is the ladle from which the hot metal is poured, and I is apot which may be provided to receive the overflow metal from the runnersG.

to secure by Letters Patent, is-

The process of joining the two halves of a brass digester-cylinder, Aand B, by a fused joint, D, cast in a mold, which consists in embeddingthe lower part,B, in the molding-floor, top edge up, then forming themold for the joint with its suitable gate F, runners G, and annularopeningP, then suspending edge down within the mold the upper part, A,then running the hot metal through the mold until complete fusion hastaken place, then closing the runners, finally lowering the upper partof the cylinder as the metal at the joint cools, substantially as setforth.

WILLIAM T. GARRATT.

Witnesses JOHN RAEEERTY, GEO. PARDY.

and the mold being completely filled is left to What I claim as myinvention, and desire

